[Crash-utility] [PATCH v2 03/10] back_trace: don't check /proc if !LOCAL_ACTIVE()

[Dave Anderson]

----- Original Message -----
> On 04/25, Oleg Nesterov wrote:
> >
> > -	if (ACTIVE() && !INSTACK(esp, bt)) {
> > +	if (LOCAL_ACTIVE() && !INSTACK(esp, bt)) {
> 
> Of course, this is wrong, please see v2 below.
> 
> -------------------------------------------------------------------------------
> Subject: [PATCH v2 03/10] back_trace: don't check /proc if !LOCAL_ACTIVE()
> 
> Obviously the /proc/$tc->pid check can only make sense if LOCAL_ACTIVE().
> 
> Signed-off-by: Oleg Nesterov <oleg at redhat.com>
> ---
>  kernel.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/kernel.c b/kernel.c
> index a6fa7a6..cf0a6a0 100644
> --- a/kernel.c
> +++ b/kernel.c
> @@ -2902,7 +2902,7 @@ back_trace(struct bt_info *bt)
>  
>  	if (ACTIVE() && !INSTACK(esp, bt)) {
>  		sprintf(buf, "/proc/%ld", bt->tc->pid);
> -		if (!file_exists(buf, NULL))
> +		if (!(LOCAL_ACTIVE() && file_exists(buf, NULL)))
>  			error(INFO, "task no longer exists\n");
>  		else
>  			error(INFO,
> --
> 2.5.0
 
This doesn't make sense to me.  If it's !LOCAL_ACTIVE() (i.e. hybrid-live-dump), then
why would you want to call file_exists()?  

Shouldn't it be: LOCAL_ACTIVE() and !file_exists()

Dave